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Date:   Sun, 24 Mar 2019 13:19:01 +0100
From:   Greg KH <gregkh@linuxfoundation.org>
To:     Bharath Vedartham <linux.bhar@gmail.com>
Cc:     jfrederich@gmail.com, dsd@laptop.org, jon.nettleton@gmail.com,
        devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org
Subject: Re: [RFC/PATCH] staging: olpc_dcon: Use WARN_ON instead of BUG_ON
Message-ID: <20190324121901.GB6569@kroah.com>
References: <20190324121208.GA24213@bharath12345-Inspiron-5559>
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On Sun, Mar 24, 2019 at 05:42:08PM +0530, Bharath Vedartham wrote:
> This is with respect to a checkpatch.pl CHECK: "Avoid crashing the
> kernel. Use WARN_ON instead of BUG_ON". But I maybe wrong here. Is a
> kernel crash desired if olpc_board_at_least(olpc_board(0xc2)) fails,
> will there be inconsistent results if execution continues?
> 
> Signed-off-by: Bharath Vedartham <linux.bhar@gmail.com>
> ---
>  drivers/staging/olpc_dcon/olpc_dcon.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/olpc_dcon/olpc_dcon.c b/drivers/staging/olpc_dcon/olpc_dcon.c
> index 6b714f7..900baab7 100644
> --- a/drivers/staging/olpc_dcon/olpc_dcon.c
> +++ b/drivers/staging/olpc_dcon/olpc_dcon.c
> @@ -138,7 +138,7 @@ static int dcon_bus_stabilize(struct dcon_priv *dcon, int is_powered_down)
>  	}
>  	if (x < 0) {
>  		pr_err("unable to stabilize dcon's smbus, reasserting power and praying.\n");
> -		BUG_ON(olpc_board_at_least(olpc_board(0xc2)));
> +		WARN_ON(olpc_board_at_least(olpc_board(0xc2)));

Shouldn't you do something to handle this error, if it can actually
happen?  Don't just warn and keep on going, if this was all that was
needed to fix up these types of issues, we could do it all in one simple
search/replace step :)

thanks,

greg k-h